Method of compounding rosin, rosin oil, and polyisobutylene



Patented June 21, 1949 auasos METHOD OF COMPOUNDING ROSIN, BOSIN OIL, AND POLYISOBUTYLENE Henry N. Padowicz, Livingston, N. 1., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York No Drawing. Application January 10, 1947, Serial No. 721,482

I 2 Claims. (01. 260-27) This invention relates to a method of compounding a composition and more particularly to a method of compounding a fluxlng cement.

Electrical cables, particularly as used in the communications arts, have long been protected by extruded seamless sheaths of lead or various alloys of lead, which are highly satisfactory in most respects, except as to the weight necessarily added to the cable by this material. To provide equally efficient protective sheathing of less weight, cables have recently been produced having one or more transversely corrugated thin tapes of harder, tougher metal than lead, e. g. iron, copper, brass, zinc or others, folded longitudinally about the core of the cable, with the over-lapped edges of the tape making a seam lying longitudinally along the cable, which seam is hermetically closed by soldering. To further ensure tightness of the seam, in some instances, the corrugated tape has its inner corrugations filled and its whole inner surface covered with a suitable thermoplastic cement such as that described in U. S. Patent 2,216,435 issued Octoher 1, 1940. to J. F. Eckel, the essential ingre- I dients of which are rosin, rosin oil and polyicobutylene. The range or variety of materials available for a cement for this particular use appears to be limited since the composition employed must not only be adhesive and thermoplastic over a wide range of temperature in subsequent use, but must also tend to assist rather than hinder the effecting of a tight union of the overlapped metal tape edges when these are being soldered together. The compound must be both a thermoplastic cement and a flux. However the physical natures of the three ingredients are such that the blending of them into a smoothly even texturedcompound is extremely d flicult on a commercial scale. The polyisobutyiene is of a toughly rubbery consistency. rosin oil is a slick, smoothly repellant liquid; and rosin is a brittle, easily powdered yet faintly tacky pseudo solid.

An object of the present invention is to provide a suitable. satisfactory and successful method of compounding rosin. rosin oil and polyisobutylene to form a mixture of smoothly even texture and substantially homogeneous composition throughout its mass.

With the above and other objects in view, the invention may be embodied in a method comprising steps of heating rosin and rosin oil together to a temperature and for a time sufficient to form a wholly liquid, uniform mixture of the two, cooling the liquid mixture so formed to a temperature at which it is still liquid. but de- 2 cidedly viscous, and then working polyisobutyieno into the viscous rosin-rosin oil mixture.

Other objects and features of the invention will appear from the following detailed description thereof: Amounts of rosin and of rosin oil ,representing the desired ratio of each to the other are placed in any suitablereceptacle and heated to a temperature of from 230 to 250 F. for as long as is necessary to reduce the charge of material to a fluently liquid state of complete and uniform intermixture.of the two components. The charge is then allowed to cool, or may be cooled by any suitable means if desired, until its physical state is still definitely liquid but decidedly viscous, which will be a temperature of from to 220' 1". depending upon the relative proportions of the a two ingredients. The polyisobutylene is then worked into the viscously fluid mixture by stirring, kneading and working until the whole mass assumes a uniform consistency and a. substantially uniform composition.

What is claimed is:

1. The method of compounding rosin, rosin oil and polyisobutylene, which method comprises steps of heating rosin and rosin oil together until a uniform mixture of fluently liquid physical character is obtained, cooling the fluently liquid mixture until it assumes a viscously liquid state. and working nol'yis obutylene into. the viscous liquid until a three component compound of uniform physical state and substantially uniform composition is obtained.

2. The method of compounding rosin, rosin oil and polyisobutylene, which method comprises. steps of heating rosin and rosin oil together at a temperature of from 230 -to 250 F. until a uniform mixture of fluently liquid physical character is obtained, cooling the fluently liquid mixture until it assumes at a temperature of from 150 to 220 1". a viscously liquid state, and working polyisobutylene into the viscous liquid until a three component compound of uniform physical state and substantially uniform composition is obtained.

HENRY N. PADOWICZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

